Holding back in communications with clinicians: Patient and care partner perspectives in Parkinson's disease

Objectives

To describe how patients with Parkinson's disease (PD) and care partners choose to share or withhold information from clinicians.

Methods

This is a qualitative, descriptive study nested within a multisite, randomized clinical trial of outpatient palliative care compared to standard neurologic care for PD. Interviews with patients (n = 30) and care partners (n = 30) explored experiences communicating with neurology clinicians. Thematic analyses identified themes relevant to patient-care partner-clinician communication.

Results

There were four themes relevant to sharing and/or withholding information from clinicians: (1) Suppressing Concerns During Visits, (2) Care Partner Awareness of Patients' Communication Barriers due to Cognitive Impairment, (3) Limited Sharing of Sensitive or Intimate Issues by Patients and Care Partners, and (4) Patient and Care Partner Suggestions to Overcome 'Holding Back'.

Conclusion

Limitations to communication between patients, care partners, and clinicians should be acknowledged and recognized in routine Parkinson's disease care to foster accurate disclosure of unmet palliative care and other needs. Triadic communication strategies may help patients and care partners talk about unmet palliative care needs.

Innovation

By recognizing that cognitive impairment and sensitive topics can be barriers, clinicians can adjust or adopt targeted communication strategies for identifying and discussing care needs.

Aerobic exercise improves depressive symptoms in the unilateral 6-OHDA-lesioned rat model of Parkinson's disease

Aerobic exercise has been shown to have established benefits on motor function in Parkinson's disease (PD). However, the impact of exercise on depressive symptoms in PD remains unclear. This study aimed to investigate the effects of regular exercise, specifically using a forced running wheel, on both motor performance and the prevalence of depression in a unilateral 6-OHDA-lesioned rat model of PD. The behavioral outcomes of exercise were assessed through the rotarod test (RT), forelimb adjusting step test (FAST), sucrose consumption test (SCT), and novelty sucrose splash test (NSST). Our data revealed evident depressive symptoms in the PD animals, characterized by reduced sucrose consumption in the SCT and diminished exploratory activity in the NSST compared to the naïve control group. Specifically, after 11 weeks of exercise, the PD exercise group demonstrated the most significant improvements in sucrose consumption in the SCT. Additionally, this group exhibited reduced immobility and increased exploratory behavior compared to the PD control group in the NSST. Furthermore, the PD exercise group displayed the greatest improvement in correcting forelimb stepping bias. Our results suggested that a regimen of running wheel exercise enhances motor abilities and mitigates the occurrence of depressive behaviors caused by 6-OHDA dopamine depletion in the PD rat model.

Correlation between 25-hydroxy-vitamin D and Parkinson's disease

Background

Previous cross-sectional studies have shown that Parkinson's disease (PD) patients have lower serum 25-hydroxyvitamin D (25(OH)D) concentrations than controls. Other studies have not yet tested whether research findings from other regions are generalizable to Chinese populations. In this case-control study, we examined the correlation between 25-hydroxyvitamin D and Parkinson's disease.

Methods

We established an association between 25-hydroxyvitamin D deficiency and PD in a case-control study of 100 PD patients and 100 control subjects free of neurological disease at the First Affiliated Hospital of Xinjiang Medical University.

Results

Total 25-hydroxyvitamin D levels were deficient in 21 % of patients with PD compared with 4 % of controls. In univariate analyses, plasma levels of 25-hydroxyvitamin D were associated with PD (p < 0.001). In multivariate analyses, vitamin D deficiency (25(OH)D < 20 ng/mL) was significantly associated with PD (p = 0.008, Odds Ratio =17.13, 95 % CI= 2.082-141.075). Individuals with 25(OH)D levels in the lowest quartile had the highest prevalence of PD (p = 0.026, OR=11.786, 95 % CI =1.342-103.51 compared to individuals with values in the highest quartile).

Conclusions

Our study reveals an association between 25-hydroxyvitamin D and PD. Patients with incident PD had significantly lower serum 25(OH)D concentrations than age-matched controls. High-risk PD patients with vitamin D deficiency who have not yet developed exercise impairment should undergo vitamin D measurement and any necessary treatment as soon as possible. Limitations of the study: the study needs further assessment of populations with low vitamin D levels in other regions of China; further assessment of the effect of different sources of vitamin D on PD; further study of longitudinal cohorts at different time points.

Sinomenine exerts a neuroprotective effect on PD mouse model through inhibiting PI3K/AKT/mTOR pathway to enhance autophagy

BACKGROUND

Parkinson's disease (PD), as a chronic and progressive neurodegenerative disease, is associated with autophagy. This study focused on the regulation of sinomenine (SN) on autophagy in PD and its related mechanism.

METHODS

The PD mouse model was constructed by MPTP inducement, and the mouse motor function after modeling and SN treatment was examined by rotarod, grip strength, and foot printing tests. Tyrosine hydroxylase (TH)/LC3B-positive neurons in the substantia nigra pars compacta of mouse brains were detected by immunofluorescence. The expressions of proteins related to autophagy (Beclin1, p62, LC3-I and LC3-II) and phosphorylated phosphoinositide 3-kinase (PI3K)/AKT/mechanistic target of rapamycin kinase (mTOR) signaling pathway were measured by western blot. Rescue experiments were performed to determine the effects of MHY1485 (mTOR activator) on SN-treated PD mice.

RESULTS

SN potentiated the motor ability in PD mice, promoted the survival of dopaminergic neurons, increased the protein expression level of Beclin1, LC3-II/LC3-I ratio and LC3B-positive neurons, lowered the protein expression level of p62 and inactivated PI3K/AKT/mTOR pathway in the substantia nigra tissue of mouse brains. Moreover, MHY1485 reversed the above effects of SN on PD mice via reactivating PI3K/AKT/mTOR pathway.

CONCLUSION

SN augments the autophagy of dopaminergic neurons via inhibiting the PI3K/AKT/mTOR pathway and exerts a neuroprotective effect on PD mice.

Aspartame use and Parkinson's disease: review of associated effects on neurotransmitters, oxidative stress, and cognition

Objective: The purpose of this review was to assess the current evidence regarding the associated physiological and cognitive effects of aspartame (APM) consumption and Parkinson's Disease (PD).

METHODS

A total of 32 studies demonstrating effects of APM on monoamine deficiencies, oxidative stress, and cognitive changes were reviewed.

RESULTS

Multiple studies demonstrated decreased brain dopamine, decreased brain norepinephrine, increased oxidative stress, increased lipid peroxidation, and decreased memory function in rodents after APM use. In addition, PD animal models have been found to be more sensitive to the effects of APM.

DISCUSSION

Overall, studies of APM use over time yielded more consistent results; however, no study has examined long-term effects on APM in human PD patients. Based on the current evidence, long-term human based observational research is needed to further investigate the potential effect of APM on PD.

Objective assessment of the effects of opicapone in Parkinson's disease through kinematic analysis

BACKGROUND

Opicapone (OPC) is a third-generation, selective peripheral COMT inhibitor that improves peripheral L-DOPA bioavailability and reduces OFF time and end-of-dose motor fluctuations in Parkinson's disease (PD) patients.

OBJECTIVES

In this study, we objectively assessed the effects of adding OPC to L-DOPA on bradykinesia in PD through kinematic analysis of finger movements.

METHODS

We enrolled 20 treated patients with PD and motor fluctuations. Patients underwent two experimental sessions (L-DOPA, L-DOPA + OPC), separated by at least 1 week. In each session, patients were clinically evaluated and underwent kinematic movement analysis of repetitive finger movements at four time points: (i) before their usual morning dose of L-DOPA (T0), (ii) 30 min (T1), (iii) 1 h and 30 min (T2), and (iv) 3 h and 30 min after the L-DOPA intake (T3).

RESULTS

Movement velocity and amplitude of finger movements were higher in PD patients during the session with OPC compared to the session without OPC at all the time points tested. Importantly, the variability of finger movement velocity and amplitude across T0-T3 was significantly lower in the L-DOPA + OPC than L-DOPA session.

CONCLUSIONS

This study is the first objective assessment of the effects of adding OPC to L-DOPA on bradykinesia in patients with PD and motor fluctuations. OPC, in addition to the standard dopaminergic therapy, leads to significant improvements in bradykinesia during clinically relevant periods associated with peripheral L-DOPA dynamics, i.e., the OFF state in the morning, delayed-ON, and wearing-OFF periods.

Promising use of metformin in treating neurological disorders: biomarker-guided therapies

Neurological disorders are a diverse group of conditions that affect the nervous system and include neurodegenerative diseases (Alzheimer's disease, multiple sclerosis, Parkinson's disease, Huntington's disease), cerebrovascular conditions (stroke), and neurodevelopmental disorders (autism spectrum disorder). Although they affect millions of individuals around the world, only a limited number of effective treatment options are available today. Since most neurological disorders express mitochondria-related metabolic perturbations, metformin, a biguanide type II antidiabetic drug, has attracted a lot of attention to be repurposed to treat neurological disorders by correcting their perturbed energy metabolism. However, controversial research emerges regarding the beneficial/detrimental effects of metformin on these neurological disorders. Given that most neurological disorders have complex etiology in their pathophysiology and are influenced by various risk factors such as aging, lifestyle, genetics, and environment, it is important to identify perturbed molecular functions that can be targeted by metformin in these neurological disorders. These molecules can then be used as biomarkers to stratify subpopulations of patients who show distinct molecular/pathological properties and can respond to metformin treatment, ultimately developing targeted therapy. In this review, we will discuss mitochondria-related metabolic perturbations and impaired molecular pathways in these neurological disorders and how these can be used as biomarkers to guide metformin-responsive treatment for the targeted therapy to treat neurological disorders.

Neuroprotective effects of polyphyllin VI against rotenone-induced toxicity in SH-SY5Y cells

BACKGROUND

A substantial body of evidence is drawing connections between Parkinson's disease (PD) and the phenomena of oxidative stress and mitochondrial dysfunction. Polyphyllin VI (PPVI), an active compound found in Rhizoma Paridis-commonly known as Chonglou (CL) in China, has been identified for its various pharmacological properties, including anti-tumor and anti-inflammatory effects.

OBJECTIVE

In the present study, an in vitro model of PD was established by treating SH-SY5Y cells with rotenone (ROT), to evaluate the potential neuroprotective effects of polyphyllin VI and its underlying mechanism.

METHODS

SH-SY5Y cells were treated with ROT to establish an in vitro model of PD. The effects of polyphyllin VI on cell viability were assessed using the resazurin assay. Cell morphology was examined using a microscope. The YO-PRO-1/PI was used to detect apoptosis. Mito-Tracker Red CMXRos, Mito-Tracker Green, and JC-1 were used to detect the effects of polyphyllin Ⅵ on mitochondrial viability, morphology, and function. Oxidative stress-related marker detection kits were used to identify the effects of polyphyllin VI on oxidative stress. Western blot analysis was employed to investigate the signaling pathways associated with neuroprotection.

RESULTS

PPVI increased ROT-induced SH-SY5Y cell viability and improved ROT-induced cellular morphological changes. PPVI ameliorated ROT-induced oxidative stress status, and attenuated mitochondrial function and morphological changes. PPVI may exert neuroprotective effects through FOXO3α/CREB1/DJ-1-related signaling pathways.

CONCLUSION

These preliminary findings suggested that PPVI possesses neuroprotective attributes in vitro, and it may be a potential candidate for PD treatment. However, extensive research is necessary to fully understand the mechanisms of PPVI and its effectiveness both in vitro and in vivo.

Antisense therapy: a potential breakthrough in the treatment of neurodegenerative diseases

Neurodegenerative diseases are a group of disorders characterized by the progressive degeneration of neurons in the central or peripheral nervous system. Currently, there is no cure for neurodegenerative diseases and this means a heavy burden for patients and the health system worldwide. Therefore, it is necessary to find new therapeutic approaches, and antisense therapies offer this possibility, having the great advantage of not modifying cellular genome and potentially being safer. Many preclinical and clinical studies aim to test the safety and effectiveness of antisense therapies in the treatment of neurodegenerative diseases. The objective of this review is to summarize the recent advances in the development of these new technologies to treat the most common neurodegenerative diseases, with a focus on those antisense therapies that have already received the approval of the U.S. Food and Drug Administration.

Altered functional-structural coupling may predict Parkinson's patient's depression

We aimed to elucidate the neurobiological basis of depression in Parkinson's disease and identify potential imaging markers for depression in patients with Parkinson's disease. We recruited 43 normal controls (NC), 46 depressed Parkinson's disease patients (DPD) and 56 non-depressed Parkinson's disease (NDPD). All participants underwent routine T2-weighted, T2Flair, and resting-state scans on the same 3.0 T magnetic resonance imaging (MRI) scanner at our hospital. Pre-processing includes calculating surface-based Regional Homogeneity (2DReHo) and cortical thickness. Then we defined the correlation coefficient between 2DReHo and cortical thickness as the functional-structural coupling index. Between-group comparisons were conducted on the Fisher's Z-transformed correlation coefficients. To identify specific regions of decoupling, the 2DReHo for each participant were divided by cortical thickness at each vertex, followed by threshold-free cluster enhancement (TFCE) multiple comparison correction. Binary logistic regression analysis was performed with DPD as the dependent variable, and significantly altered indicators as the independent variables. Receiver operating characteristic curves were constructed to compare the diagnostic performance of individual predictors and combinations using R and MedCalc software. DPD patients exhibited a significantly lower whole-brain functional-structural coupling index than NDPD patients and NC. Abnormal functional-structural coupling was primarily observed in the left inferior parietal lobule and right primary and early visual cortices in DPD patients. Receiver operating characteristic analysis revealed that the combination of cortical functional-structural coupling, surface-based ReHo, and thickness had the best diagnostic performance, achieving a sensitivity of 65% and specificity of 77.7%. This is the first study to explore the relationship between functional and structural changes in DPD patients and evaluate the diagnostic performance of these altered correlations to predict depression in Parkinson's disease patients. We posit that these changes in functional-structural relationships may serve as imaging biomarkers for depression in Parkinson's disease patients, potentially aiding in the classification and diagnosis of Parkinson's disease. Additionally, our findings provide functional and structural imaging evidence for exploring the neurobiological basis of depression in Parkinson's disease.

The autophagy protein Atg9 functions in glia and contributes to parkinsonian symptoms in a Drosophila model of Parkinson's disease

Parkinson's disease is a progressive neurodegenerative disease characterized by motor deficits, dopaminergic neuron loss, and brain accumulation of α-synuclein aggregates called Lewy bodies. Dysfunction in protein degradation pathways, such as autophagy, has been demonstrated in neurons as a critical mechanism for eliminating protein aggregates in Parkinson's disease. However, it is less well understood how protein aggregates are eliminated in glia, the other cell type in the brain. In the present study, we show that autophagy-related gene 9 (Atg9), the only transmembrane protein in the autophagy machinery, is highly expressed in Drosophila glia from adult brain. Results from immunostaining and live cell imaging analysis reveal that a portion of Atg9 localizes to the trans-Golgi network, autophagosomes, and lysosomes in glia. Atg9 is persistently in contact with these organelles. Lacking glial atg9 reduces the number of omegasomes and autophagosomes, and impairs autophagic substrate degradation. This suggests that glial Atg9 participates in the early steps of autophagy, and hence the control of autophagic degradation. Importantly, loss of glial atg9 induces parkinsonian symptoms in Drosophila including progressive loss of dopaminergic neurons, locomotion deficits, and glial activation. Our findings identify a functional role of Atg9 in glial autophagy and establish a potential link between glial autophagy and Parkinson's disease. These results may provide new insights on the underlying mechanism of Parkinson's disease.

Does the Montreal Cognitive Assessment (MoCA) identify cognitive impairment profiles in Parkinson's disease? An exploratory study

An important proportion of patients with Parkinson's Disease (PD) present signs of cognitive impairment, although this is heterogeneous. In an attempt to classify this, the dual syndrome hypothesis distinguishes between two profiles: one defined by attentional and executive problems with damage in anterior cerebral regions, and another with mnesic and visuospatial alterations, with damage in posterior cerebral regions. The Montreal Cognitive Assessment (MoCA) is one of the recommended screening tools, and one of the most used, to assess cognitive impairment in PD. However, its ability to specifically identify these two profiles of cognitive impairment has not been studied. The aim of this study was, therefore, to analyze the capacity of the MoCA to detect cognitive impairment, and also to identify anterior and posterior profiles defined by the dual syndrome hypothesis. For this purpose, 59 patients with idiopathic PD were studied with the MoCA and a neuropsychological battery of tests covering all cognitive domains. Results of logistic regression analysis with ROC (Receiver Operating Characteristic) curves showed that MoCA detected cognitive impairment and identified patients with a profile of anterior/attentional and executive deficit, with acceptable sensibility and specificity. However, it did not identify patients with a posterior/mnesic-visuospatial impairment. We discuss the reasons for the lack of sensitivity of MoCA in this profile, and other possible implications of these results with regards the usefulness of this tool to assess cognitive impairment in PD.

6-Hydroxy-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline Demonstrates Neuroprotective Properties in Experimental Parkinson's Disease by Enhancing the Antioxidant System, Normalising Chaperone Activity and Suppressing Apoptosis

Parkinson's disease (PD) is a neurodegenerative disease, whereby disturbances within the antioxidant defence system, increased aggregation of proteins, and activation of neuronal apoptosis all have a crucial role in the pathogenesis. In this context, exploring the neuroprotective capabilities of compounds that sustain the effectiveness of cellular defence systems in neurodegenerative disorders is worthwhile. During this study, we assessed how 6-hydroxy-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline (HTHQ), which has antioxidant properties, affects the functioning of the antioxidant system, the activity of NADPH-generating enzymes and chaperones, and the level of apoptotic processes in rats with rotenone-induced PD. Six groups of animals were formed for our experiment, each with 12 animals. These were: a control group, animals with rotenone-induced PD, rats with PD given HTHQ at a dose of 50 mg/kg, rats with PD given HTHQ at a dose of 25 mg/kg, animals with pathology who were administered a comparison drug rasagiline, and control animals who were administered HTHQ at a dose of 50 mg/kg. The study results indicate that administering HTHQ led to a significant decrease in oxidative stress in PD rats. The enhanced redox status in animal tissues was linked with the recovery of antioxidant enzyme activities and NADPH-generating enzyme function, as well as an upsurge in the mRNA expression levels of antioxidant genes and factors Nrf2 and Foxo1. Administering HTHQ to rats with PD normalized the chaperone-like activity and mRNA levels of heat shock protein 70. Rats treated with the compound displayed lower apoptosis intensity when compared to animals with pathology. Therefore, owing to its antioxidant properties, HTHQ demonstrated a beneficial impact on the antioxidant system, resulting in decreased requirements for chaperone activation and the inhibition of apoptosis processes triggered in PD. HTHQ at a dose of 50 mg/kg had a greater impact on the majority of the examined variables compared to rasagiline.

Sleep and Overactive Bladder in Parkinson's Disease

Patients with Parkinson's disease (PD) have disturbances in their bladder and sleep physiology that lead to nocturia and overactive bladder (OAB). These symptoms can be extremely bothersome and impact not only their quality of life (QoL) but also the QoL of their caretakers. We aim to highlight the changes in bladder and sleep physiology in PD and explore OAB/nocturia treatment strategies in this population.

Hyperglycemia affects axial signs in patients with Parkinson's disease through mechanisms of insulin resistance or non-insulin resistance

OBJECTIVE

To investigate the influence of hyperglycemia on motor symptoms, especially axial signs, and potential mechanisms related to insulin resistance (IR) in patients with Parkinson's disease (PWP).

METHODS

According to glycated hemoglobin (HbA1c) level, PWP were divided into the low-HbA1c and the high-HbA1c groups. Demographic information, glucose metabolism-related variables, Hoehn-Yahr stage, and motor function were compared between the two groups. Correlations between levels of HbA1c and the homeostatic model assessment (HOMA)-IR and motor function in PWP were further analyzed.

RESULTS

HbA1c level was significantly and positively correlated with the Movement Disorder Society Unified Parkinson's Disease Rating Scale Part III score, axial signs subscore, the Timed Get Up and Go test time, the center of pressure displacement of standing with eyes open and closed, and significantly and negatively correlated with the 10-m walk test comfortable gait speed. HOMA-IR level was significantly and negatively correlated with 10-m walk test comfortable gait speed, but not with others.

CONCLUSIONS

PWP with high HbA1c showed worse axial symptoms, including dysfunction of automatic walking, dynamic balance, and postural control than those with low HbA1c. In PWP, the effects of hyperglycemia on automatic walking speed may be associated with the IR-related mechanisms, and the effects on dynamic balance and postural control may be related to mechanisms other than IR.

Effects of facial biofeedback on hypomimia, emotion recognition, and affect in Parkinson's disease

OBJECTIVES

Facial expressions are a core component of emotions and nonverbal social communication. Therefore, hypomimia as secondary symptom of Parkinson's disease (PD) has adverse effects like social impairment, stigmatization, under-diagnosis and under-treatment of depression, and a generally lower quality of life. Beside unspecific dopaminergic treatment, specific treatment options for hypomimia in PD are rarely investigated. This quasi-randomized controlled trial evaluated the short-term effects of facial electromyogram (EMG) based biofeedback to enhance facial expression and emotion recognition as nonverbal social communication skills in PD patients. Furthermore effects on affect are examined.

METHOD

A sample of 34 in-patients with PD were allocated either to facial EMG-biofeedback as experimental group or non-facial exercises as control group. Facial expression during posing of emotions (measured via EMG), facial emotion recognition, and positive and negative affect were assessed before and after treatment. Stronger improvements were expected in the EMG-biofeedback in comparison to the control group.

RESULTS

The facial EMG-biofeedback group showed significantly greater improvements in overall facial expression, and especially for happiness and disgust. Also, overall facial emotion recognition abilities improved significantly stronger in the experimental group. Positive affect was significantly increased in both groups with no significant differences between them, while negative affect did not change within both groups.

CONCLUSIONS

The study provides promising evidence for facial EMG-biofeedback as a tool to improve facial expression and emotion recognition in PD. Embodiment theories are discussed as working mechanism.

SNHG14 Elevates NFAT5 Expression Through Sequestering miR-375-3p to Promote MPP + -Induced Neuronal Apoptosis, Inflammation, and Oxidative Stress in Parkinson's Disease

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the loss of dopaminergic neurons. LncRNA small nucleolar RNA host gene 14 (SNHG14) was found to promote neuron injury in PD. Here, we investigated the mechanisms of SNHG14 in PD process. In vivo or in vitro PD model was established by using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mice or 1-methyl-4-phenylpyridinium (MPP +)-stimulated SK-N-SH cells. The expression of genes and proteins was measured by qRT-PCR and Western blot. In vitro assays were conducted using ELISA, CCK-8, colony formation, EdU, flow cytometry, and Western blot assays, respectively. The oxidative stress was evaluated by determining the production of superoxide dismutase (SOD) and malondialdehyde (MDA). The direct interactions between miR-375-3p and NFAT5 (Nuclear factor of activated T-cells 5) or SNHG14 was verified using dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. SNHG14 and NFAT5 were elevated, while miR-375-3p was decreased in MPTP-mediated PD mouse model and MPP + -induced SK-N-SH cells. Knockdown of SNHG14 or NFAT5, or overexpression of miR-375-3p reversed MPP + -induced neuronal apoptosis, inflammation, and oxidative stress. Mechanistically, SNHG14 directly bound to miR-375, which targeted NFAT5. Inhibition of miR-375-3p abolished the inhibitory activity of SNHG14 knockdown on MPP + -evoked neuronal damage. Besides that, NFAT5 up-regulation counteracted the effects of miR-375-3p on MPP + -mediated neuronal damage. SNHG14 contributed to MPP + -induced neuronal injury by miR-375/NFAT5 axis, suggesting a new insight into the pathogenesis of PD.

Unraveling brain diseases: The promise of brain-on-a-chip models

Brain disorders, encompassing a wide spectrum of neurological and psychiatric conditions, present a formidable challenge in modern medicine. Despite decades of research, the intricate complexity of the human brain still eludes comprehensive understanding, impeding the development of effective treatments. Recent advancements in microfluidics and tissue engineering have led to the development of innovative platforms known as "Brain-on-a-Chip" (BoC) i.e., advanced in vitro systems that aim to replicate the microenvironment of the brain with the highest possible fidelity. This technology offers a promising test-bed for studying brain disorders at the cellular and network levels, providing insights into disease mechanisms, drug screening, and, in perspective, the development of personalized therapeutic strategies. In this review, we provide an overview of the BoC models developed over the years to model and understand the onset and progression of some of the most severe neurological disorders in terms of incidence and debilitation (stroke, Parkinson's, Alzheimer's, and epilepsy). We also report some of the cutting-edge therapeutic approaches whose effects were evaluated by means of these technologies. Finally, we discuss potential challenges, and future perspectives of the BoC models.

Association between major dietary patterns and Parkinson's disease risk: a case-control study

BACKGROUND

There has been emerging attention to investigate the possible role of some dietary factors in the pathogenesis of Parkinson's disease (PD); however, evidence about the relationship between dietary components and the risk of PD is limited. The aim of this study was to determine the association between major dietary patterns and the risk of PD.

METHODS

This case-control study was performed on 105 patients with newly diagnosed PD and 215 healthy controls. Diagnosis of Parkinson's disease was made based on the UK Brain Bank criteria. Usual dietary intakes were collected by a validated semi-quantitative food frequency questionnaire. Dietary patterns were detected by principal component analysis.

RESULTS

Four dietary patterns, including traditional, healthy, western, and light dietary patterns, were identified. After considering all potential confounders, individuals with the highest tertile of traditional dietary pattern scores had a lower risk of PD than those with the lowest tertile (OR: 0.002; 95% CI: 0.000-0.016). A similar inverse association between the healthy pattern (OR: 0.314; 95% CI: 0.131-0.750) and light pattern (OR: 0.282; 95% CI: 0.121-0.654) and risk of PD was revealed. In contrast, adherence to the western dietary pattern was associated with PD incidence (OR: 7.26; 95% CI: 2.76-19.09).

CONCLUSIONS

The findings of this study suggest that adherence to western dietary pattern could increase the risk of PD by approximately seven times. However, the traditional, healthy, and light dietary patterns had an inverse relationship with PD risk.

Salidroside Mediated the Nrf2/GPX4 Pathway to Attenuates Ferroptosis in Parkinson's Disease

Parkinson's Disease (PD) is characterized by the loss of dopaminergic neurons, with ferroptosis playing a significant role. Salidroside (SAL) has shown neuroprotective potential, this study aims to explore its capacity to mitigate ferroptosis in PD, focusing on the modulation of the Nuclear Factor E2-Related Factor 2 (Nrf2)/ Glutathione Peroxidase 4 (GPX4) pathway. Male C57BL/6 mice were subjected to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to induce PD-like symptoms, followed by SAL and Nrf2 inhibitor administration. Then behavioral tests, immunohistochemical staining, transmission electron microscopy, and Western blot analysis were conducted to assess motor functions, pathological changes, ferroptosis, and related protein expressions. In vitro, SH-SY5Y cells were treated with erastin to induce ferroptosis to assess the protective effects of SAL. Additionally, A53T-α-synuclein (α-syn) was used to stimulate the PD model, SAL and a Nrf2 inhibitor (ML385) was utilized to elucidate the role of the Nrf2/GPX4 pathway in mitigating ferroptosis in PD. In vivo, SAL significantly improved motor functions and reduced the expression of α-syn, while increasing tyrosine hydroxylase (TH) expression of PD mice. Additionally, SAL treatment notably enhanced the levels of antioxidants and reduced MDA and iron content in the substantia nigra of PD mice. In vitro, SAL treatment increased the TH, GPX4, Nrf2 expression, and mitochondrial membrane potential whereas alleviated ferroptosis through the Nrf2/GPX4 pathway, as evidenced in erastin-induced and α-syn overexpressing SH-SY5Y cells. While these effects were reversed upon Nrf2 inhibition. SAL demonstrates significant potential in mitigating PD pathology and ferroptosis, positioning the Nrf2/GPX4 pathway as a promising therapeutic target. However, future studies should focus on the long-term effects of SAL, its pharmacokinetics, addressing the multifactorial nature of PD pathogenesis.

Mitophagy in neurodegenerative disease pathogenesis

Mitochondria are critical cellular energy resources and are central to the life of the neuron. Mitophagy selectively clears damaged or dysfunctional mitochondria through autophagic machinery to maintain mitochondrial quality control and homeostasis. Mature neurons are postmitotic and consume substantial energy, thus require highly efficient mitophagy pathways to turn over damaged or dysfunctional mitochondria. Recent evidence indicates that mitophagy is pivotal to the pathogenesis of neurological diseases. However, more work is needed to study mitophagy pathway components as potential therapeutic targets. In this review, we briefly discuss the characteristics of nonselective autophagy and selective autophagy, including ERphagy, aggrephagy, and mitophagy. We then introduce the mechanisms of Parkin-dependent and Parkin-independent mitophagy pathways under physiological conditions. Next, we summarize the diverse repertoire of mitochondrial membrane receptors and phospholipids that mediate mitophagy. Importantly, we review the critical role of mitophagy in the pathogenesis of neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Last, we discuss recent studies considering mitophagy as a potential therapeutic target for treating neurodegenerative diseases. Together, our review may provide novel views to better understand the roles of mitophagy in neurodegenerative disease pathogenesis.

Large-scale functional network connectivity mediates the association between nigral neuromelanin hypopigmentation and motor impairment in Parkinson's disease

Neuromelanin hypopigmentation within substantia nigra pars compacta (SNc) reflects the loss of pigmented neurons, which in turn contributes to the dysfunction of the nigrostriatal and striato-cortical pathways in Parkinson's disease (PD). Our study aims to investigate the relationships between SN degeneration manifested by neuromelanin reduction, functional connectivity (FC) among large-scale brain networks, and motor impairment in PD. This study included 68 idiopathic PD patients and 32 age-, sex- and education level-matched healthy controls who underwent neuromelanin-sensitive magnetic resonance imaging (MRI), functional MRI, and motor assessments. SN integrity was measured using the subregional contrast-to-noise ratio calculated from neuromelanin-sensitive MRI. Resting-state FC maps were obtained based on the independent component analysis. Subsequently, we performed partial correlation and mediation analyses in SN degeneration, network disruption, and motor impairment for PD patients. We found significantly decreased neuromelanin within SN and widely altered inter-network FCs, mainly involved in the basal ganglia (BG), sensorimotor and frontoparietal networks in PD. In addition, decreased neuromelanin content was negatively correlated with the dorsal sensorimotor network (dSMN)-medial visual network connection (P = 0.012) and dSMN-BG connection (P = 0.004). Importantly, the effect of SN neuromelanin hypopigmentation on motor symptom severity in PD is partially mediated by the increased connectivity strength between BG and dSMN (indirect effect =  - 1.358, 95% CI: - 2.997, - 0.147). Our results advanced our understanding of the interactions between neuromelanin hypopigmentation in SN and altered FCs of functional networks in PD and suggested the potential of multimodal metrics for early diagnosis and monitoring the response to therapies.

Increased Risk of New-Onset Parkinson's Disease Following a Diagnosis of Retinal Vascular Occlusion: A 14-Year Cohort Study

BACKGROUND

Although the role of the vascular component in the pathophysiology of Parkinson's disease is widely accepted and retinal vascular abnormalities are commonly observed in Parkinson's disease patients, evidence connecting retinal vascular disorders with the risk of developing Parkinson's disease is limited. We aimed to investigate the association between retinal vascular occlusion (RVO) and the risk of developing Parkinson's disease in people over 60 years using a nationwide cohort.

METHODS

From the 14-year South Korean National Health Insurance Service-Senior cohort, 11 210 incident RVO patients and 11 210 propensity scores, risk-matched controls were included. The incidence of Parkinson's disease was estimated with a Poisson regression. A Cox proportional hazards regression model was used to investigate the associations between RVO and the risk of Parkinson's disease.

RESULTS

The incidence of Parkinson's disease was 664.4 cases per 100 000 person-years (95% confidence interval [CI], 599.7-736.0) in the RVO cohort. Individuals with RVO had an increased incidence of Parkinson's disease (hazard ratio [HR], 1.28; 95% CI: 1.10-1.49). Increased PD risk was predominantly observed in retinal artery occlusion patients (HR, 1.53; 95% CI: 1.11-2.12), male patients (HR, 1.67; 95% CI: 1.29-2.17), and 5 years after diagnosis (HR, 1.46; 95% CI: 1.10-1.93).

CONCLUSIONS

Our findings suggest that a common pathophysiological pathway, such as vasculature changes, may exist between RVO and Parkinson's disease. RVO may be one of the risk factors associated with future development of Parkinson's disease. The nature of this association warrants further investigation.

Longitudinal Mediating Effect of Depression on the Relationship between Excessive Daytime Sleepiness and Activities of Daily Living in Parkinson's Disease

OBJECTIVES

Whether depression affects activities of daily living (ADLs) in patients with Parkinson's disease (PD) via excessive daytime sleepiness (EDS) remains unclear; moreover, few longitudinal studies have been conducted.

METHODS

We recruited 421 patients from the Parkinson's Progression Markers Initiative. We constructed a latent growth mediation model to explore the longitudinal mediating effect of depression on the relationship between EDS and ADLs.

RESULTS

EDS (p < .001) and depression scores (p < .001) both increased, and ADL scores (p < .001) decreased. Moreover, EDS was positively correlated with depression, whereas an increase in EDS significantly reduced ADLs. The initial value (95% confidence interval [CI]: 0.026, 0.154) and the rate of change (95% CI: 0.138, 0.514) of self-reported depression measured using the Geriatric Depression Scale(GDS) partially mediated the association between EDS and ADL score.

CONCLUSIONS

The indirect effect of the longitudinal changes of depression on the relationship between EDS and ADLs highlights the importance of depression changes in PD patients with EDS.

CLINICAL IMPLICATIONS

Depression should be considered a mediator by clinicians; preventing the worsening of depression is essential for improving ADLs in patients with PD, especially those with EDS.

The functional brain connectome in isolated rapid eye movement sleep behavior disorder and Parkinson's disease

BACKGROUND

Isolated rapid-eye-movement behavior disorder (iRBD) often precedes the development of alpha-synucleinopathies such as Parkinson's disease (PD). Magnetic resonance imaging (MRI) studies have revealed structural brain alterations in iRBD partially resembling those observed in PD. However, relatively little is known about whole-brain functional brain alterations in iRBD. Here, we characterize the functional brain connectome of iRBD compared with PD patients and healthy controls (HC) using resting-state functional MRI (rs-fMRI).

METHODS

Eighteen iRBD subjects (67.3 ± 6.6 years), 18 subjects with PD (65.4 ± 5.8 years), and 39 age- and sex-matched HC (64.4 ± 9.2 years) underwent rs-fMRI at 3 T. We applied a graph theoretical approach to analyze the brain functional connectome at the global and regional levels. Data were analyzed using both frequentist and Bayesian statistics.

RESULTS

Global connectivity was largely preserved in iRBD and PD individuals. In contrast, both disease groups displayed altered local connectivity mainly in the motor network, temporal cortical regions including the limbic system, and the visual system. There were some group specific alterations, and connectivity changes were pronounced in PD individuals. Overall, however, there was a good agreement of the connectome changes observed in both disease groups.

CONCLUSIONS

This study provides evidence for widespread functional brain connectivity alterations in iRBD, including motor circuitry, despite normal motor function. Connectome alterations showed substantial resemblance with those observed in PD, underlining a close pathophysiological relationship of iRBD and PD.

Association between motor symptoms of Parkinson's disease and swallowing disorders

BACKGROUND

Parkinson's disease (PD) presents with motor symptoms that hinder physical activity. This study aimed to thoroughly investigate swallowing dysfunction in patients with PD using videofluoroscopy (VF) and the Movement Disorder Society (MDS)-Unified PD Rating Scale (UPDRS) sub-scores.

METHODS

This study was part of an intervention project to evaluate the effectiveness of cervical percutaneous interferential current stimulation in patients with Hoehn and Yahr stages 2-4 PD. Baseline data, including swallowing-related indicators such as VF, were obtained and compared to the MDS-UPDRS sub-scores including rigidity, tremor, postural instability/gait difficulty, and limb scores.

RESULTS

Twenty-seven patients were included in this study. In the VF analysis, laryngeal penetration/aspiration, oral cavity residue, epiglottic vallecular residue, and pharyngeal residue were observed with remarkable frequency. The multivariate analysis revealed that the mean rigidity score of UPDRS was an independent and significantly correlated factor with laryngeal penetration/aspiration during the ingestion of 10 mL of water (odds ratio 1.294, 95% confidence interval 1.035-1.617; p = 0.024).

CONCLUSION

This study revealed a correlation between muscle rigidity and laryngeal penetration or aspiration risk. The detailed comparative analysis of various individual PD symptoms and swallowing disorders was substantial, which enabled early detection of the risk of swallowing disorder and the implementation of appropriate measures.

TRIAL REGISTRATION NUMBER

jRCTs062220013.

Development and internal validation of a prognostic model for loss of balance and falls in mid- to late-stage Parkinson's disease

BACKGROUND

Mid- to late-stage Parkinson's disease (PD) is often linked with worsened and significant impairment of motor activities, but existing prognostic markers do not adequately capture the risk of loss of balance in PD patients. This study aims to develop a risk prognostic model for mid- to late-stage PD and identify prognostic factors that are indicative of impending loss of balance and falls.

METHODS

The study included 307 participants of which 75 were diagnosed with idiopathic PD and 232 were neurological or non-neurological controls. Among the PD group, 46 were early-stage (Hoehn and Yahr [H&Y] = 1,2) with no significant loss of balance while 29 were mid- to late-stage (H&Y = 3,4,5) which is characterized by loss of balance and falls. Multivariable logistic regression (MLR) was used to develop a prognostic model for mid- to late-stage PD. Model discrimination was assessed by ROC curves. The model was internally validated through bootstrapping and calibration plots.

RESULTS

The relevant factors identified and included in the final MLR model were shortness of breath, age, swollen joints, heme oxygenase-1 (HO-1) protein, and total salivary protein. The model had an AUC of 0.82 (95% CI = 0.71-0.92) and was well calibrated (calibration slope = 0.77, intercept = 0.03). The likelihood of shortness of breath (OR = 7.91, 95% CI = 1.63-45.12) was significantly higher among mid- to late-stage PD than early-stage. Age and total salivary protein were also significantly higher among mid- to late-stage PD.

CONCLUSION

The MLR prognostic model for mid- to late-stage PD may assist physicians in identifying patients at high risk for loss of balance and falls.

DJ-1 protects cell death from a mitochondrial oxidative stress due to GBA1 deficiency

BACKGROUND

GBA1 mutations are the most common genetic risk factor for development of Parkinson's disease (PD). The loss of catalytic activity in GBA1, as well as the reduction of the GBA1 protein in certain cellular compartment, may increase disease progression. However, the mechanisms underlying cellular dysfunction caused by GBA1 deficiency are still mostly unknown.

OBJECTIVE

In this study, we focus on the genetic interaction between GBA1 deficiency and PD-causing genes, such as DJ-1, in mitochondrial dysfunction.

METHODS

GBA1 knockout (KO) SH-SY5Y cells were used to assess DJ-1 functions against oxidative stress in vitro. The levels of cellular reactive oxygen species were monitored with MitoSOX reagent. The expression of the PARK7 gene was analyzed using the quantitative real-time PCR (qRT-PCR). To understand the mechanism underlying DJ-1 upregulation in GBA1 KO cells, we assess ROS levels, antioxidant protein, and cell viability in GBA1 KO cells with treatment of ROS inhibitor N-acetyl-cysteine or miglustat, which is an inhibitor of glucosylceramide synthase. Dopaminergic degeneration was assessed from Gba1 L444P heterozygous mice mated with Park7 knockout mice.

RESULTS

We find that DJ-1 is significantly upregulated in GBA1 KO cells. Elevated levels of DJ-1 are attributed to the transcriptional expression of PARK7 mRNA, but not the inhibition of DJ-1 protein degradation. Because DJ-1 expression is highly linked to oxidative stress, we observe cellular reactive oxygen species (ROS) in GBA1 KO cells. Moreover, several antioxidant gene expressions and protein levels are increased in GBA1 KO cells. To this end, GBA1 KO cells are more susceptible to H2O2-induced cell death. Importantly, there is a significant reduction in dopaminergic neurons in the midbrain from Gba1 L444P heterozygous mice mated with Park7 knockout mice, followed by mild motor dysfunction.

CONCLUSION

Taken together, our results suggest that DJ-1 upregulation due to GBA1 deficiency has a protective role against oxidative stress. It may be supposed that mutations or malfunctions in the DJ-1 protein may have disadvantages in the survival of dopaminergic neurons in the brains of patients harboring GBA1 mutations.

Consistent abnormal activity in the putamen by dopamine modulation in Parkinson's disease: A resting-state neuroimaging meta-analysis

OBJECTIVE

This study aimed to elucidate brain areas mediated by oral anti-parkinsonian medicine that consistently show abnormal resting-state activation in PD and to reveal their functional connectivity profiles using meta-analytic approaches.

METHODS

Searches of the PubMed, Web of Science databases identified 78 neuroimaging studies including PD OFF state (PD-OFF) versus (vs.) PD ON state (PD-ON) or PD-ON versus healthy controls (HCs) or PD-OFF versus HCs data. Coordinate-based meta-analysis and functional meta-analytic connectivity modeling (MACM) were performed using the activation likelihood estimation algorithm.

RESULTS

Brain activation in PD-OFF vs. PD-ON was significantly changed in the right putamen and left inferior parietal lobule (IPL). Contrast analysis indicated that PD-OFF vs. HCs had more consistent activation in the right paracentral lobule, right middle frontal gyrus, right thalamus, left superior parietal lobule and right putamen, whereas PD-ON vs. HCs elicited more consistent activation in the bilateral middle temporal gyrus, left occipital gyrus, right inferior frontal gyrus and right caudate. MACM revealed coactivation of the right putamen in the direct contrast of PD-OFF vs. PD-ON. Subtraction analysis of significant coactivation clusters for PD-OFF vs. PD-ON with the medium of HCs showed effects in the sensorimotor, top-down control, and visual networks. By overlapping the MACM maps of the two analytical strategies, we demonstrated that the coactivated brain region focused on the right putamen.

CONCLUSIONS

The convergence of local brain regions and co-activation neural networks are involved the putamen, suggesting its potential as a specific imaging biomarker to monitor treatment efficacy.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD CRD42022304150].

In-vitro Approaches to Investigate the Detrimental Effect of Light on Dopaminergic Neurons

Our recent study revealed that fluorescent lamp light can penetrate deep into the brain of mice and rats leading to the development of typical histological characteristics associated with Parkinson's disease such as the loss of dopamine neurons in the substantia nigra. Monochromatic LED lights were thus used in this work to deepen our knowledge on the effects of the major wavelength peaks of fluorescent light on mouse and human dopaminergic cells. In particular, we exposed immortalized dopaminergic MN9D neuronal cells, primary cultures of mouse mesencephalic dopaminergic cells and human dopaminergic neurons differentiated from induced pluripotent stem cells (hiPSC) to different LED light wavelengths. We found that chronic exposure to LED light reduced overall undifferentiated MN9D cell number, with the most significant effects observed at wavelengths of 485 nm and 610 nm. Moreover, LED light especially at 610 nm was able to negatively impact on the survival of mouse mesencephalic dopaminergic cells and of human dopaminergic neurons derived from hiPSC. Notably, differentiated MN9D dopaminergic cells, which closely resemble mature dopamine neuronal phenotype, acutely exposed for 3 h at 610 nm, showed a clear increase in ROS production and cytotoxicity compared to controls undifferentiated MN9D cells. These increases were even more pronounced by the co-treatment with the oxidative agent H2O2. Collectively, these findings suggest that specific wavelengths, particularly those capable of penetrating deep into the brain, could potentially pose an environmental hazard in relation to Parkinson's disease.

Surface Modification of Ultrasonic Cavitation by Surfactants Improves Detection Sensitivity of α-Synuclein Amyloid Seeds

The rapid amplification and sensitive detection of α-synuclein (αSyn) seeds is an efficient approach for the early diagnosis of Parkinson's disease. Ultrasonication stands out as a promising method for the rapid amplification of αSyn seeds because of its robust fibril fragmentation capability. However, ultrasonication also induces the primary nucleation of αSyn monomers, deteriorating the seed detection sensitivity by generating seed-independent fibrils. In this study, we show that an addition of surfactants to the αSyn monomer solution during αSyn seed detection under ultrasonication remarkably improves the detection sensitivity of the αSyn seeds by a factor of 100-1000. Chemical kinetic analysis reveals that these surfactants reduce the rate of primary nucleation while promoting the fragmentation of the αSyn fibrils under ultrasonication. These effects are attributed to the modification of the ultrasonic cavitation surface by the surfactants. Our study enhances the utility of ultrasonication in clinical assays targeting αSyn seeds as the Parkinson's disease biomarker.

Attenuating mitochondrial dysfunction and morphological disruption with PT320 delays dopamine degeneration in MitoPark mice

BACKGROUND

Mitochondria are essential organelles involved in cellular energy production. Changes in mitochondrial function can lead to dysfunction and cell death in aging and age-related disorders. Recent research suggests that mitochondrial dysfunction is closely linked to neurodegenerative diseases. Glucagon-like peptide-1 receptor (GLP-1R) agonist has gained interest as a potential treatment for Parkinson's disease (PD). However, the exact mechanisms responsible for the therapeutic effects of GLP-1R-related agonists are not yet fully understood.

METHODS

In this study, we explores the effects of early treatment with PT320, a sustained release formulation of the GLP-1R agonist Exenatide, on mitochondrial functions and morphology in a progressive PD mouse model, the MitoPark (MP) mouse.

RESULTS

Our findings demonstrate that administration of a clinically translatable dose of PT320 ameliorates the reduction in tyrosine hydroxylase expression, lowers reactive oxygen species (ROS) levels, and inhibits mitochondrial cytochrome c release during nigrostriatal dopaminergic denervation in MP mice. PT320 treatment significantly preserved mitochondrial function and morphology but did not influence the reduction in mitochondria numbers during PD progression in MP mice. Genetic analysis indicated that the cytoprotective effect of PT320 is attributed to a reduction in the expression of mitochondrial fission protein 1 (Fis1) and an increase in the expression of optic atrophy type 1 (Opa1), which is known to play a role in maintaining mitochondrial homeostasis and decreasing cytochrome c release through remodeling of the cristae.

CONCLUSION

Our findings suggest that the early administration of PT320 shows potential as a neuroprotective treatment for PD, as it can preserve mitochondrial function. Through enhancing mitochondrial health by regulating Opa1 and Fis1, PT320 presents a new neuroprotective therapy in PD.

Investigation of total cerebellar and flocculonodular lobe volume in Parkinson's disease and healthy individuals: a brain segmentation study

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disorder with an unexplored link to the cerebellum. In the pathophysiology of balance disorders in PD, the role of the flocculonodular lobe (FL) is linked to the impairment of the dopaminergic system. Dopamine deficiency can also lead to changes in cerebellum functions, disrupting balance control. This study compares cerebellar and FL volumes between healthy controls (HC) and PD patients, analyzing their correlation with clinical outcomes.

METHODS

We used magnetic resonance images of 23 PD patients (14 male, 9 female) and 24 HC (9 male, 15 female). Intracranial (ICV), total cerebellar, FL, and cerebellar gray matter volumes were measured using VolBrain. Clinical outcomes in PD patients were assessed using the Unified Parkinson's Disease Rating Scale (UPDRS-III) to evaluate motor function, with scores correlated to volumetric data.

RESULTS

The cerebellar and gray matter volumes in HC were 115.53 ± 10.44 cm3 and 84.83 ± 7.76 cm3, respectively, compared to 126.83 ± 13.47 cm3 and 92.37 ± 9.45 cm3 in PD patients, indicating significantly larger volumes in PD patients (p < 0.05). The flocculonodular lobe gray matter volume was 1.14 ± 0.19 cm3 in PD patients and 1.02 ± 0.13 cm3 in HC, but there was a significant increase in gray matter volume in PD patients between the groups (p < 0.05). In PD patients, significant negative correlations were observed between FL volume and the UPDRS-III scores (r =  - 0.467, p = 0.033) and between UPDRS-III scores and both total (r =  - 0.453, p = 0.039) and normalized (r =  - 0.468, p = 0.032) gray matter volumes of the FL.

CONCLUSION

Although total gray matter volumes were larger in PD patients, the volumes of FL did not differ between groups. In Parkinson's disease, increased cerebellar volume may regulate fine motor movements rather than balance.

Does Parkinson's disease affect sleep quality?

BACKGROUND

Parkinson's disease (PD) is a common neurodegenerative disease that is linked to several motor and nonmotor symptoms, including sleep disturbances. Patient quality of life has been shown to be disproportionally impacted by disease.

OBJECTIVES

To investigate sleep quality among individuals with PD, and to assess the severity of sleep disturbances and their impact on daytime activities.

SUBJECTS AND METHODS

A case‒control with 44 patients with Parkinson's disease and 80 apparently healthy control participants was recruited from several hospitals and clinics. Each participant provided a thorough medical history and underwent a physical examination, and a questionnaire comprising the standard PSQI was used to assess sleep quality. Independent samples t test and Spearman's correlation analysis were used with a p value equal to or less than 0.05 which was considered significant.

RESULTS

The mean global PSQI score was 11.55 ± 4.412 for PD patients and 5.73 ± 3.22 for the control group with significant p value, Sleep latency onset was 75.57 min for PD patients and 22.81 min for the control group with significant p value. There was no significant correlation between age and other sleep-related variables. A total of 86.4% of patients with Parkinson's disease suffered from varying degrees of daytime dysfunction compared to 61.25% of the controls.

CONCLUSION

Parkinson's disease patients had poorer sleep quality than the controls. Age and sex were not found to be expected as a factor for sleep quality in patients with Parkinson's disease. Daytime dysfunction rates are high in patients with Parkinson's disease.

Association between Religiousness and Quality of Life among Patients in Brazil diagnosed with Idiopathic Parkinson's Disease

The importance of religiousness in idiopathic Parkinson's disease (IPD) has been the subject of conflicting research. The impact of religiousness on quality of life and depressive symptoms has also been poorly studied in this population. This study investigated the correlation between religiousness and quality of life in patients with IPD. We evaluated 37 patients with IPD (according to the criteria of the Movement Disorders Society) who were from an outpatient clinic specializing in movement disorders in Brazil. We assessed the patients using the Duke University Religion Index and scales for motor impairment, cognition, quality of life, and depression. Spearman's test was used to check for possible correlations between the different dimensions of religiousness and the clinical variables analyzed. Patients with a worse quality of life and more depressive symptoms showed greater intrinsic religiousness.

Protective Effect of Resveratrol Combined with Levodopa Against Oxidative Damage in Dopaminergic Neurons

Levodopa (L-3,4-dihydroxyphenylalanine, L-Dopa) alleviates the symptoms of Parkinson's disease (PD), yet prolonged usage may give rise to severe adverse effects. Resveratrol (RSV) is a potent antioxidant, anticancer and anti-inflammatory agent. And a variety of polyphenol antioxidant compounds derived from RSV combined with levodopa have demonstrated neuroprotective activity against neuronal cell death. The purpose of this study was to examine the impact of this combination of RSV and L-Dopa on the survival rate, growth status, and reactive oxygen species (ROS) of MES23.5 dopamine (DA) neuron cells. In this study, we induced MPP+ in MES23.5 dopamine neuron cells and observed their survival rate, growth status, ROS content, as well as the effect of RSV combined with L-Dopa on cell survival. We also measured malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity levels as indicators of mitochondrial function, oxidative stress, and oxidative damage in the cells. Our results indicated that the MES23.5 dopamine neurons had decreased survival, poor growth status, and increased ROS content after MPP+ induction. Moreover, we found that MDA levels were elevated, and SOD activity levels were decreased, suggesting that the cells experienced abnormal mitochondrial function. However, when RSV was combined with L-Dopa, the cells showed a reduced level of MPP + -induced oxidative damage, with a more significant inhibitory effect observed in the RSV group at a concentration of 50 μmol/L. In conclusion, we found that the effects of co-administration of RSV with L-Dopa (100 μmol/L) was more effective than L-Dopa administered at the high dose. Thus, we found that RSV has the potential to reduce the dose of L-Dopa required to improve PD symptoms.

A dynamic brain network decomposition method discovers effective brain hemodynamic sub-networks for Parkinson's disease

OBJECTIVE

Dopaminergic treatment is effective for Parkinson's disease (PD). Nevertheless, the conventional treatment assessment mainly focuses on human-administered behavior examination while the underlying functional improvements have not been well explored. This paper aims to investigate brain functional variations of PD patients after dopaminergic therapy. Approach. This paper proposed a dynamic brain network decomposition method and discovered brain hemodynamic sub-networks that well characterized the efficacy of dopaminergic treatment in PD. Firstly, a clinical walking procedure with functional near-infrared spectroscopy (fNIRS) was developed, and brain activations during the procedure from fifty PD patients under the OFF and ON states (without and with dopaminergic medication) were captured. Then, dynamic brain networks were constructed with sliding-window analysis of phase lag index and integrated time-varying functional networks across all patients. Afterwards, an aggregated network decomposition algorithm was formulated based on aggregated effectiveness optimization of functional networks in spanning network topology and cross-validation network variations, and utilized to unveil effective brain hemodynamic sub-networks for PD patients. Further, dynamic sub-network features were constructed to characterize the brain flexibility and dynamics according to the temporal switching and activation variations of discovered sub-networks, and their correlations with differential treatment-induced gait alterations were analyzed. Results. The results demonstrated that PD patients exhibited significantly enhanced flexibility after dopaminergic therapy within a sub-network related to the improvement of motor functions. Other sub-networks were significantly correlated with trunk-related axial symptoms and exhibited no significant treatment-induced dynamic interactions. Significance. The proposed method promises a quantified and objective approach for dopaminergic treatment evaluation. Moreover, the findings suggest that the gait of PD patients comprises distinct motor domains, and the corresponding neural controls are selectively responsive to dopaminergic treatment. .

Immunotherapy with an antibody against CD1d modulates neuroinflammation in an α-synuclein transgenic model of Lewy body like disease

The neuroinflammatory process in synucleinopathies of the aging population such as Parkinson's disease (PD) and dementia with Lewy bodies (DLB) involves microglial activation as well as infiltration of the CNS by T cells and natural killer T cells (NKTs). To evaluate the potential of targeting NKT cells to modulate neuroinflammation, we treated α-syn transgenic (tg) mice (e.g.: Thy1 promoter line 61) with an antibody against CD1d, which is a glycoprotein expressed in antigen presenting cells (APCs). CD1d-presented lipid antigens activate NKT cells through the interaction with T cell receptor in NKTs, resulting in the production of cytokines. Thus, we hypothesized that blocking the APC-NKT interaction with an anti-CD1d antibody might reduce neuroinflammation and neurodegeneration in models of DLB/PD. Treatment with the anti-CD1d antibody did not have effects on CD3 (T cells), slightly decreased CD4 and increased CD8 lymphocytes in the mice. Moreover, double labeling studies showed that compared to control (IgG) treated α-syn tg mice, treatment with anti-CD1d decreased numbers of CD3/interferon γ (IFN γ)-positive cells, consistent with NKTs. Further double labeling studies showed that CD1d-positive cells co-localized with the astrocytes marker GFAP and that anti-CD1d antibody reduced this effect. While in control α-syn tg mice CD3 positive cells were near astrocytes, this was modified by the treatment with the CD1d antibody. By qPCR, levels of IFN γ, CCL4, and interleukin-6 were increased in the IgG treated α-syn tg mice. Treatment with CD1d antibody blunted this cytokine response that was associated with reduced astrocytosis and microgliosis in the CNS of the α-syn tg mice treated with CD1d antibody. Flow cytometric analysis of immune cells in α-syn tg mice revealed that CD1d-tet + T cells were also increased in the spleen of α-syn tg mice, which treatment with the CD1d antibody reduced. Reduced neuroinflammation in the anti-CD1d-treated α-syn tg mice was associated with amelioration of neurodegenerative pathology. These results suggest that reducing infiltration of NKT cells with an antibody against CD1d might be a potential therapeutical approach for DLB/PD.

Mitochondrial import stress and PINK1-mediated mitophagy: the role of the PINK1-TOMM-TIMM23 supercomplex

Mutations in the PINK1 kinase cause Parkinson disease (PD) through physiological processes that are not yet fully elucidated. PINK1 kinase accumulates selectively on damaged mitochondria, where it recruits the E3 ubiquitin ligase PRKN/Parkin to mediate mitophagy. Upon mitochondrial import failure, PINK1 accumulates in association with the translocase of outer mitochondrial membrane (TOMM). However, the molecular basis of this PINK1 accumulation on the TOMM complex remain elusive. We recently demonstrated that TIMM23 (translocase of the inner mitochondrial membrane 23) is a component of the PINK1-supercomplex formed in response to mitochondrial stress. We also uncovered that PINK1 is required for the formation of this supercomplex and highlighted the biochemical regulation and significance of this supercomplex; expanding our understanding of mitochondrial quality control and PD pathogenesis.

Current trends in basic research on Parkinson's disease: from mitochondria, lysosome to α-synuclein

Parkinson's disease (PD) is a neurodegenerative disorder characterized by progressive degeneration of dopaminergic neurons in the substantia nigra and other brain regions. A key pathological feature of PD is the abnormal accumulation of α-synuclein protein within affected neurons, manifesting as Lewy bodies and Lewy neurites. Despite extensive research efforts spanning several decades, the underlying mechanisms of PD and disease-modifying therapies remain elusive. This review provides an overview of current trends in basic research on PD. Initially, it discusses the involvement of mitochondrial dysfunction in the pathogenesis of PD, followed by insights into the role of lysosomal dysfunction and disruptions in the vesicular transport system. Additionally, it delves into the pathological and physiological roles of α-synuclein, a crucial protein associated with PD pathophysiology. Overall, the purpose of this review is to comprehend the current state of elucidating the intricate mechanisms underlying PD and to outline future directions in understanding this disease.

Advanced therapies in Parkinson's disease: an individualized approach to their indication

Device aided therapies (DAT) comprising the intrajejunal administration of levodopa/carbidopa intestinal gel (LCIG) and levodopa/carbidopa/entacapone intestinal gel (LECIG), the continuous subcutaneous application of foslevodopa/foscarbidopa or apomorphine infusion (CSAI) and deep brain stimulation (DBS) are used to treat Parkinson's disease with insufficient symptom alleviation under intensified pharmacotherapy. These DAT significantly differ in their efficacy profiles, indication, invasiveness, contraindications, and potential side effects. Usually, the evaluation of all these procedures is conducted simultaneously at the same point in time. However, as disease progression and symptom burden is extremely heterogeneous, clinical experience shows that patients reach the individual milestones for a certain therapy at different points in their disease course. Therefore, advocating for an individualized therapy evaluation for each DAT, requiring an ongoing evaluation. This necessitates that, during each consultation, the current symptomatology should be analyzed, and the potential suitability for a DAT be assessed. This work represents a critical interdisciplinary appraisal of these therapies in terms of their individual profiles and compares these DAT regarding contraindications, periprocedural considerations as well as their efficacy regarding motor- and non-motor deficits, supporting a personalized approach.

Nicotine restores olfactory function by activation of prok2R/Akt/FoxO3a axis in Parkinson's disease

BACKGROUND

Olfactory dysfunction occurs frequently in Parkinson's disease (PD). In this study, we aimed to explore the potential biomarkers and underlying molecular pathways of nicotine for the treatment of olfactory dysfunction in 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced PD mice.

METHODS

MPTP was introduced into C57BL/6 male mice to generate a PD model. Regarding in vivo experiments, we performed behavioral tests to estimate the protective effects of nicotine in MPTP-induced PD mice. RNA sequencing and traditional molecular methods were used to identify molecules, pathways, and biological processes in the olfactory bulb of PD mouse models. Then, in vitro experiments were conducted to evaluate whether nicotine can activate the prok2R/Akt/FoxO3a signaling pathway in both HEK293T cell lines and primary olfactory neurons treated with 1-methyl-4-phenylpyridinium (MPP+). Next, prok2R overexpression (prok2R+) and knockdown (prok2R-) were introduced with lentivirus, and the Akt/FoxO3a signaling pathway was further explored. Finally, the damaging effects of MPP+ were evaluated in prok2R overexpression (prok2R+) HEK293T cell lines.

RESULTS

Nicotine intervention significantly alleviated olfactory and motor dysfunctions in mice with PD. The prok2R/Akt/FoxO3a signaling pathway was activated after nicotine treatment. Consequently, apoptosis of olfactory sensory neurons was significantly reduced. Furthermore, prok2R+ and prok2R- HEK293T cell lines exhibited upregulation and downregulation of the Akt/FoxO3a signaling pathway, respectively. Additionally, prok2R+ HEK293T cells were resistant to MPP+-induced apoptosis.

CONCLUSIONS

This study showed the effectiveness and underlying mechanisms of nicotine in improving hyposmia in PD mice. These improvements were correlated with reduced apoptosis of olfactory sensory neurons via activated prok2R/Akt/FoxO3a axis. These results explained the potential protective functions of nicotine in PD patients.

Self-Reported Voice and Swallow Questionnaires' Alignment with Unified Parkinson's Disease Rating Scale Questions: A Preliminary Study

PURPOSE

The purpose of this manuscript was twofold: to investigate how clinical voice and swallow questionnaires align with self-reports from speech/voice and swallow domains of the Unified Parkinson's Disease Rating Scale (UPDRS), and how decline in self-reported speech/voice measures predict decline in self-reported swallowing measures.

METHODS

This observational, preliminary cross-sectional study included 15 people diagnosed with Idiopathic Parkinson's Disease. Participants completed the Voice Related Quality of Life (V-RQOL), Sydney Swallow Questionnaire (SSQ), and cognitive screening (Montreal Cognitive Assessment; MoCA) to account for cognitive impairment during self-reported speech/voice and swallow measures. They also completed the speech/voice and swallow components of the UPDRS.

RESULTS

There were significant associations between the SSQ and UPDRS question 2.3 (chewing/swallowing) (P < 0.001), but not between UPDRS question 2.1 (speech/voice) and V-RQOL. However, the MoCA was significantly and directionally associated with V-RQOL scores (P = 0.01). Finally, the V-RQOL was significantly associated with SSQ scores in a multiple regression model (P = 0.02).

CONCLUSIONS

Speech/voice and swallow-related questions from the UPDRS may be viable initial screening tools to facilitate faster and earlier laryngeal function testing. Substantially more research should be undertaken to assess how well these UPDRS question domains are indicative of underlying speech/voice or swallow dysfunction.

Evidence of heat sensitivity in people with Parkinson's disease

Examining how heat affects people with Parkinson's disease is essential for informing clinical decision-making, safety, well-being, and healthcare planning. While there is evidence that the neuropathology associated with Parkinson's disease affects thermoregulatory mechanisms, little attention has been given to the association of heat sensitivity to worsening symptoms and restricted daily activities in people with this progressive disease. Using a cross-sectional study design, we examined the experiences of people diagnosed with Parkinson's disease in the heat. Two-hundred and forty-seven people completed an online survey (age: 66.0 ± 9.2 years; sex: male = 102 (41.3%), female = 145 (58.7%)), of which 195 (78.9%) reported becoming more sensitive to heat with Parkinson's disease. Motor and nonmotor symptoms worsened with heat in 182 (73.7%) and 203 (82.2%) respondents, respectively. The most commonly reported symptoms to worsen included walking difficulties, balance impairment, stiffness, tremor, fatigue, sleep disturbances, excess sweating, difficulty concentrating, and light-headedness when standing. Concerningly, over half indicated an inability to work effectively in the heat, and nearly half reported that heat impacted their ability to perform household tasks and social activities. Overall, heat sensitivity was common in people with Parkinson's disease and had a significant impact on symptomology, day-to-day activities and quality of life.

Parkinson's disease and vitamins: a focus on vitamin B12

Parkinson's disease (PD) has been linked to a vast array of vitamins among which vitamin B12 (Vit B12) is the most relevant and often investigated specially in the context of intrajejunal levodopa infusion therapy. Vit B12 deficiency, itself, has been reported to cause acute parkinsonism. Nevertheless, concrete mechanisms through which B12 deficiency interacts with PD in terms of pathophysiology, clinical manifestation and progression remains unclear. Recent studies have suggested that Vit B12 deficiency along with the induced hyperhomocysteinemia are correlated with specific PD phenotypes characterized with early postural instability and falls and more rapid motor progression, cognitive impairment, visual hallucinations and autonomic dysfunction. Specific clinical features such as polyneuropathy have also been linked to Vit B12 deficiency specifically in context of intrajejunal levodopa therapy. In this review, we explore the link between Vit B12 and PD in terms of physiopathology regarding dysfunctional neural pathways, neuropathological processes as well as reviewing the major clinical traits of Vit B12 deficiency in PD and Levodopa-mediated neuropathy. Finally, we provide an overview of the therapeutic effect of Vit B12 supplementation in PD and posit a practical guideline for Vit B12 testing and supplementation.

Influence of cognitive reserve on cognitive and motor function in α-synucleinopathies: A systematic review and multilevel meta-analysis

Cognitive reserve has shown promise as a justification for neuropathologically unexplainable clinical outcomes in Alzheimer's disease. Recent evidence suggests this effect may be replicated in conditions like Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. However, the relationships between cognitive reserve and different cognitive abilities, as well as motor outcomes, are still poorly understood in these conditions. Additionally, it is unclear whether the reported effects are confounded by medication. This review analysed studies investigating the relationship between cognitive reserve and clinical outcomes in these α-synucleinopathy cohorts, identified from MEDLINE, Scopus, psycINFO, CINAHL, and Web of Science. 85 records, containing 176 cognition and 31 motor function effect sizes, were pooled using multilevel meta-analysis. There was a significant, positive association between higher cognitive reserve and both better cognition and motor function. Cognition effect sizes differed by disease subtype, cognitive reserve measure, and outcome type; however, no moderators significantly impacted motor function. Review findings highlight the clinical implications of cognitive reserve and importance of engaging in reserve-building behaviours.

Feasibility of Somato-Cognitive Coordination Therapy Using Virtual Reality for Patients with Advanced Severe Parkinson's Disease

 This feasibility study enrolled 20 patients with advanced severe Parkinson's disease (PD) to evaluate somato-cognitive coordination therapy (SCCT) using virtual reality. Focusing on the safety and tolerability of SCCT, 17 patients (76±9 years old and 64.7% male) completed the 3-month trial. Key observations included absence of adverse events and tolerability of the participants to SCCT despite initial apprehensions and minor adjustments in medication. Physical functions showed no significant deterioration, suggesting the safety of SCCT. In conclusion, SCCT emerges as feasible and well-tolerated intervention in advanced severe PD, requiring further research to assess its therapeutic efficacy.

Transdermal Delivery of Pramipexole Using Microneedle Technology for the Potential Treatment of Parkinson's Disease

Parkinson's disease (PD) is a debilitating neurodegenerative disease primarily impacting neurons responsible for dopamine production within the brain. Pramipexole (PRA) is a dopamine agonist that is currently available in tablet form. However, individuals with PD commonly encounter difficulties with swallowing and gastrointestinal motility, making oral formulations less preferable. Microneedle (MN) patches represent innovative transdermal drug delivery devices capable of enhancing skin permeability through the creation of microconduits on the surface of the skin. MNs effectively reduce the barrier function of skin and facilitate the permeation of drugs. The work described here focuses on the development of polymeric MN systems designed to enhance the transdermal delivery of PRA. PRA was formulated into both dissolving MNs (DMNs) and directly compressed tablets (DCTs) to be used in conjunction with hydrogel-forming MNs (HFMNs). In vivo investigations using a Sprague-Dawley rat model examined, for the first time, if it was beneficial to prolong the application of DMNs and HFMNs beyond 24 h. Half of the patches in the MN cohorts were left in place for 24 h, whereas the other half remained in place for 5 days. Throughout the entire 5 day study, PRA plasma levels were monitored for all cohorts. This study confirmed the successful delivery of PRA from DMNs (Cmax = 511.00 ± 277.24 ng/mL, Tmax = 4 h) and HFMNs (Cmax = 328.30 ± 98.04 ng/mL, Tmax = 24 h). Notably, both types of MNs achieved sustained PRA plasma levels over a 5 day period. In contrast, following oral administration, PRA remained detectable in plasma for only 48 h, achieving a Cmax of 159.32 ± 113.43 ng/mL at 2 h. The HFMN that remained in place for 5 days demonstrated the most promising performance among all investigated formulations. Although in the early stages of development, the findings reported here offer a hopeful alternative to orally administered PRA. The sustained plasma profile observed here has the potential to reduce the frequency of PRA administration, potentially enhancing patient compliance and ultimately improving their quality of life. This work provides substantial evidence advocating the development of polymeric MN-mediated drug delivery systems to include sustained plasma levels of hydrophilic pharmaceuticals.

Asleep versus awake GPi DBS surgery for Parkinson's disease: A systematic review and meta-analysis

BACKGROUND

Patients with Parkinson's Disease (PD) who receive either asleep image-guided subthalamic nucleus deep brain stimulation (DBS) or the traditional awake technique have comparable motor outcomes. However, there are fewer studies regarding which technique should be chosen for globus pallidus internus (GPi) DBS. This systematic review and meta-analysis aims to compare the accuracy of lead placement and motor outcomes of asleep versus awake GPi DBS PD population.

METHODS

We systematically searched PubMed, Embase, and Cochrane for studies comparing asleep vs. awake GPi DBS lead placement in patients with PD. Outcomes were spatial accuracy of lead placement, measured by radial error between intended and actual location, motor improvement measured using (UPDRS III), and postoperative stimulation parameters. Statistical analysis was performed with Review Manager 5.1.7. and OpenMeta [Analyst].

RESULTS

Three studies met inclusion criteria with a total of 247 patients. Asleep DBS was used to treat 192 (77.7 %) patients. Follow-up ranged from 6 to 48 months. Radial error was not statistically different between groups (MD -0.49 mm; 95 % CI -1.0 to 0.02; I2 = 86 %; p = 0.06), with a tendency for higher target accuracy with the asleep technique. There was no significant difference between groups in change on motor function, as measured by UPDRS III, from pre- to postoperative (MD 8.30 %; 95 % CI -4.78 to 21.37; I2 = 67 %, p = 0.2). There was a significant difference in postoperative stimulation voltage, with the asleep group requiring less voltage than the awake group (MD -0.27 V; 95 % CI -0.46 to - 0.08; I2 = 0 %; p = 0.006).

CONCLUSION

Our meta-analysis indicates that asleep image-guided GPi DBS presents a statistical tendency suggesting superior target accuracy when compared with the awake standard technique. Differences in change in motor function were not statistically significant between groups.

Human Nasal Inferior Turbinate-Derived Neural Stem Cells Improve the Niche of Substantia Nigra Par Compacta in a Parkinson's Disease Model by Modulating Hippo Signaling

BACKGROUND

Parkinson's disease (PD) is one of the most prevalent neurodegenerative diseases, following Alzheimer's disease. The onset of PD is characterized by the loss of dopaminergic neurons in the substantia nigra. Stem cell therapy has great potential for the treatment of neurodegenerative diseases, and human nasal turbinate-derived stem cells (hNTSCs) have been found to share some characteristics with mesenchymal stem cells. Although the Hippo signaling pathway was originally thought to regulate cell size in organs, recent studies have shown that it can also control inflammation in neural cells.

METHODS

Dopaminergic neuron-like cells were differentiated from SH-SY5Y cells (DA-Like cells) and treated with 1-Methyl-4-phenylpyridinium iodide to stimulate Reactive oxidative species (ROS) production. A transwell assay was conducted to validate the effect of hNTSCs on the Hippo pathway. We generated an MPTP-induced PD mouse model and transplanted hNTSCs into the substantia nigra of PD mice via stereotaxic surgery. After five weeks of behavioral testing, the brain samples were validated by immunoblotting and immunostaining to confirm the niche control of hNTSCs.

RESULTS

In-vitro experiments showed that hNTSCs significantly increased cell survival and exerted anti-inflammatory effects by controlling ROS-mediated ER stress and hippocampal signaling pathway factors. Similarly, the in-vivo experiments demonstrated an increase in anti-inflammatory effects and cell survival rate. After transplantation of hNTSCs, the PD mouse model showed improved mobility and relief from PD symptoms.

CONCLUSION

hNTSCs improved the survival rate of dopaminergic neurons by manipulating the hippocampal pathway through Yes-associated protein (YAP)/transcriptional coactivator with a PDZ-binding motif (TAZ) by reducing inflammatory cytokines. In this study, we found that controlling the niche of hNTSCs had a therapeutic effect on PD lesions.